The Australian Transport Safety Bureau (ATSB) is Australia's national transport safety investigator. The ATSB's function is to improve safety and public confidence in the aviation, marine and rail modes of transport. The ATSB is Australia's prime agency for the independent investigation of civil aviation, rail and maritime accidents, incidents and safety deficiencies.

Fatality highlights risks on open stern OSVs

What happened

In the early hours of 14 July 2015, the offshore support vessel (OSV) Skandi Pacific was loading cargo from an oil rig about 165 km off Australia’s north-west coast. As the weather deteriorated, cargo operations were stopped and the OSV moved a short distance from the rig. Two crewmembers then began securing the cargo on the vessel’s aft deck.

While securing the cargo, the crewmembers slackened the securing chain they had used to secure the containers on the starboard side to better secure the entire stow. Shortly after, two large waves came over Skandi Pacific’s open stern, shifting the unsecured containers forward. One crewmember was trapped between the moving containers, chains and a skip and suffered fatal crush injuries.

Skandi Pacific’s aft deck Source: DOF Management

Why did it happen

The deteriorating weather conditions had resulted in the cargo operations being stopped. After the crewmembers had lashed the cargo they found two mini-containers forward were not properly secured. To secure the containers, they decided to use a secondary chain, by securing it to the crash barrier then to the primary chain. When tightened, this chain would bring the primary chain in tight against the mini-containers. Their plan required slackening the primary chain to secure the secondary.However, the sequence of working exposed them to high risk if water was shipped on Skandi Pacific’s aft deck. The crewmember attempting to fasten a securing chain forward of the two unsecured mini-containers was in a position of danger when waves came over the vessel’s open stern.

The Australian Transport Safety Bureau (ATSB) found that vessel’s managers had not adequately assessed the risks associated with shipping seas over the vessel’s stern while securing cargo on this type of vessel (the OSV had an open stern). Further, there were no clearly defined limits for excessive water on deck that necessitated stopping operations, leaving individuals to make difficult, and necessarily subjective, decisions about whether or not to stop work.

The ATSB investigation also identified that the vessel’s safety management system procedures did not contain clearly defined weather limits for working or securing cargo in adverse weather.

Safety advisory notice

MO-2015-005-SAN-005: The Australian Transport Safety Bureau advises the masters, owners and operators of all offshore support vessels to ensure that the risks associated with working on the aft deck of vessels with open sterns are adequately assessed.